Great question with a very tricky answer.
Here is what I’ve found:
Doing cardio (eliptical, tred mill, running, walking) will generally LOWER my BG levels, UNLESS I over- workout. When I don’t eat properly before doing cardio, my body will start to eat away at muscle tissues and burning fat. While technically burning fat is what we WANT to do when trying to lose weight, for diabetics, burning fat turns into creating ketones and thus, raising BG.
As a diabetic, you can lose weight, but it’s a much slower process. You have to do the cardio to increase your lean muscle and replace fat tissues with muscle instead of simply burning the fat off.
So, instead of burning 500 calories per hour (like I was doing for a while) and getting sick from it, I burn 400 calories per hour (still a strenous workout, but just enough to keep me out of spiking BG range). I have to eat something that will stay in my system for a while, like cheeses and peanut butter before working out too. Then, after working out, something like yogurt or cottage cheese keeps me feeling good.
Since going on my strict low carb diet, though, I’ve been at a loss for what kinds of foods to eat before and after. The peanut butter still works okay, but the cottage cheese and yogurt are pretty much out of the question now.
But… I’m still trying to figure it out.
Hope this helps you some.
INot a doctor, just a diabetic trying to figure it out too)